Transport container for metal alcoholates and method for transporting metal alcoholates

ABSTRACT

A transport container for metal alcoholates, comprising a rigid outer container ( 11 ), which consists primarily of renewable raw materials, and a flexible bulk material container ( 10 ), which is inside the outer container, wherein the flexible bulk material container has at least one inner diffusion-impermeable layer and an outer flexible fabric layer.

The invention relates to a transport container for metal alcoholates.

Metal alcoholates, especially magnesium alcoholates, are known chemical compounds used in the manufacture of catalysts employed for example in the manufacture of polyolefins.

Storage and transport of metal alcoholates, though, requires a number of safety precautions. Magnesium ethanolate, for example, is highly flammable, an irritant and reacts violently with water. There is a danger of self-ignition in the presence of air. This also applies analogously to other metal alcoholates.

Since metal alcoholates are sensitive to air and moisture, special precautionary measures must be taken during their transport.

The packing of magnesium alcoholate successively in two bags and then in a steel drum to exclude air and moisture is known. This type of packaging is disposable packaging. In this way drums of around 50 kg capacity can be packed and transported. This known type of packaging has the disadvantage that only a relatively small quantity can be packed in one drum and transported. A greater amount of bulk material must be packed correspondingly in a large plurality of these drums and thus cannot be transported in a sensible manner.

When magnesium alcoholate is used in the manufacture of a catalyst, amounts of up to 1000 kg per batch are used, and therefore the use of larger packaging units is useful.

The use of stainless steel silo containers, which can be filled with up to 500 kg, as transport containers for metal alcoholates is likewise known. These stainless steel silo containers are directly filled with metal alcoholate. The metal alcoholate is not filled into a bag and then into the stainless steel silo container. These containers, which are also designated as IBC (Intermediate Bulk Containers), are reusable drums with the associated disadvantages. The containers must be returned to the metal alcoholate production site. In this process, problems with damage to the steel outer container and safety-related problems often arise, since the container must be cleaned before reuse. On account of the above-mentioned properties of the residual quantities of metal alcoholate remaining in the container, special safety-related measures must be taken here. Not only in this respect must cleaning of the containers be carried out with great care, but also because the container must be freed from impurities and moisture before reuse. Steel drums as such have a large dead volume, which makes both transport of the metal alcoholates to the consumer and also the return transport very costly.

The object of the invention is to develop a method and a device with which these disadvantages can be avoided.

This object is achieved by a transport container for metal alcoholates,

comprising a rigid outer container, which consists primarily of renewable raw materials, and a flexible bulk material container, which is inside the outer container, wherein the flexible bulk material container has at least one inner diffusion-impermeable layer with a water vapor diffusion rate WDD of less than 0.3 g/(m2*d), measured at 38° C. and 90% relative humidity, according to DIN53122, and an oxygen and carbon dioxide diffusion rate q_(A)each of less than 0.3 cm3/(m2*d*bar), measured at 23° C. and 75% relative humidity, according to DIN53380, and an outer flexible fabric layer with an ultimate tensile strength warp of at least 185 daV/5 cm and an ultimate tensile strength weft of at least 150 daV/5 cm, measured according to DIN EN-ISO 13934-1 from base and side walls.

The water vapor diffusion rate of the inner layer WDD is preferably less than 0.1 g/(m2*d), measured at 38° C. and 90% relative humidity, according to DIN53122, and the oxygen and carbon dioxide diffusion rate q_(A)is less than 0.1 cm3/(m2*d*bar), measured at 23° C. and 75% relative humidity, according to DIN53380.

A rigid outer container is a dimensionally stable container made from a material such as, for example, cardboard or wood, which preferably has a strength, characterized by the puncture energy according to DIN 53142, of at least 18 J, measured at 23° C. and 50% relative humidity.

A flexible bulk material container is a container whose container shape is variable, where the container shape is developed only through the material filled into the container.

The rigid outer container may consist of a plurality of individual components, which are held together by metal clips, polymeric adhesive sheets or similar fixing means. The predominant part, i.e. at least 50 wt. %, preferably at least 70 wt. %, especially 90 wt. % of the rigid outer container consists, however, of materials which are based on renewable raw materials.

The flexible bulk material container is inserted into the rigid outer container and is enclosed by it. The inner layer and the outer layer of the flexible bulk material container can be completely or partly connected to each other or can be separate. The inner layer may consist of all sheet materials known to the expert, as long as the required diffusion rates for water vapor, oxygen and carbon dioxide are maintained. The inner layer is preferably a composite material sheet, for example an aluminum composite liner consisting of polyethylene (PE), aluminum and polyethylene terephthalate (PET). The outer layer of the flexible bulk material container preferably consists of a fabric, especially a polypropylene fabric.

Such flexible bulk material containers are also designated as FIBC (flexible intermediate bulk containers).

The flexible bulk material container may have a transport weight of up to 300 kg, preferably up to 400 kg, especially up to 500 kg. To guarantee economic transport the transport weight should be at least 200 kg.

The transport container according to the invention therefore has the same transport capacity as a stainless steel silo container but without its disadvantages, such as high weight, high price or the need for expensive return transport to the production site.

The flexible bulk material container may be grounded to avoid a dust explosion, which can be triggered by static charge, and to facilitate filling and emptying in explosion-protected areas.

The flexible bulk material container that can be used according to the invention may have a filling connector and an outlet connector. Preferably at least the inner layer of the flexible bulk material container may be welded, so that, after filling and covering with inert gas, product contamination with the atmosphere can be excluded.

The flexible bulk material container may, as shown in FIG. 1, be transported on four carry belts 3, 4, 5 and 6.

A typical flexible bulk material container that can be used according to the invention is shown schematically in FIG. 1.

The transport containers according to the present invention are to be used as disposable packaging which can be disposed of after emptying. Thus return transport to the producer can be dispensed with.

Already in this respect the transport containers according to the present invention have a clear advantage over the reusable drums made from stainless steel. The transport containers according to the present invention, however, also increase the transport efficiency compared with the reusable drums with steel containers because of their considerably lower weight. Thus, a reusable steel drum which has a transport capacity of 500 kg weighs about 260 kg, whereas the transport container according to the present invention consisting of flexible bulk material container, rigid outer container and pallet has, with a transport capacity of 500 kg, only a dead weight of an average of about 40 kg. Disposable drums according to the prior art which have a transport capacity of 50 kg per drum have a dead weight of about 125 kg with a palleted total transport quantity of 500 kg. That corresponds approximately to three times the dead weight of the transport container according to the invention with the same transported quantity.

In the case of the reusable steel drums the packing weight is about 35% of the total weight. In the case of the disposable drums according to the prior art the packing weight is about 20% of the total weight. In the case of the transport container according to the invention the packing weight is less than 15% of the total weight of the transport container filled with metal alcoholate and is thus considerably lower than in the case of the containers of the prior art. Preferably the weight of the transport container according to the invention is less than 10% of the total weight of the transport container filled with metal alcoholate.

On account of the high dead volume of the known reusable stainless steel drums and of the disposable drums, in a standard transport container only about 5 t of metal alcoholate can be transported in reusable steel drums, whereas the same standard transport container can be loaded with about 10 t of metal alcoholate in the transport containers according to the invention.

The rigid outer container made of primarily renewable raw materials preferably consists primarily of wood, especially primarily of cardboard. The cardboard may consist of corrugated cardboard and has a size adapted to that of the flexible bulk material container. At the same time the cardboard is to be structured so that at least two transport containers according to the invention can be stacked on top of each other.

The dimensions of the rigid outer container are preferably such that up to 20 transport containers each stacked on pallets can be placed in a known ship or rail container.

For example, the rigid outer container may have the following dimensions:

Inner Dimensions in Millimeters

-   L=length 1100 -   B=width 1100 -   H=height 880 -   Thickness of the walls 14 mm

Outer Dimensions in Millimeters

-   L=length 1128 (1100+14+14) -   B=width 1128 (1100+14+14) -   H=height 936 (880+14+14+14+14)

A typical rigid outer container made from cardboard, as may be used according to the invention, is shown schematically in FIG. 2.

The transport container according to the invention preferably fulfills the criteria for a combination IBC of the type 11HZ2 for the purpose of the European Agreement concerning the International Carriage of Dangerous Goods by Road (ADR) and the International Maritime Dangerous Goods Code (IMDG code). Especially preferably, the transport container according to the invention has approval for the transportation of alkaline earth metal alcoholates and for self-heatable organic solid materials according to the German regulation on carriage of dangerous goods by road, rail and inland shipping—GGVSEB and the German regulation concerning the carriage of dangerous goods by ship (regulation on carriage of dangerous goods by sea—GGVSee). According to section 3.2, Register of Dangerous Goods, of the ADR and the IMDG codes, e.g. for UN 3205 (ALKALINE EARTH METAL ALCOHOLATES, N.A.G.)and UN 3088 (SELF-HEATABLE ORGANIC SOLID MATERIAL, N.A.G.), in each case packing group II, is assigned the packaging directive IBC 06 that permits the use of a combination IBC of the type 11HZ2 as bulk packaging.

Preferably a feature of the transport containers according to the invention is that the flexible bulk material container can be removed from the transport container. A removable flexible bulk material container facilitates handling of the goods transported. During the transportation a rigid outer container provides good dimensional stability and stackability. Removal of the flexible bulk material container on site simplifies handling and emptying.

Since the transport container according to the invention is especially intended for the transport of metal alcoholates, the invention also comprises a transport container according to the invention filled with a metal alcoholate.

Preferably the metal alcoholate is selected from the group consisting of magnesium ethanolate, magnesium methanolate, magnesium isopropanolate, or mixed compounds of these; in addition the metal alcoholate may be selected from the group consisting of sodium methanolate, calcium ethanolate, calcium methanolate, carbonized magnesium alcoholate or mixtures of these.

The magnesium alcoholate may be a powder or granules consisting of magnesium alcoholates of general formula Mg(OR₁)x(OR₂)y with the proviso O<=x<=2, O<=y<=2 and x+y=2, where salts of the type (OR₁) not equal to (OR₂) and also salts of the type (OR₁)=(OR₂) and mixtures of these salts are used within the bed.

The alcoholates may also be present in carbonized solid form having the general formula Mg(OR₁)x(OR₂)y(CO₂)z.

The powder or granules may also consist of mixtures of one or more of the above-mentioned materials with other materials (up to 50 wt. %) (e.g. silicon dioxide, titanium dioxide, Mg hydroxides, Mg carbonates).

In a particularly preferred embodiment of the invention the transport container is filled with magnesium ethanolate.

The invention likewise comprises a method for transporting metal alcoholates comprising the steps

-   provision of a transport container, -   filling of the container with metal alcoholate, -   closing of the container and subsequent transportation, -   characterized in that the transport container comprises the     following components: -   a rigid outer container, which consists primarily of renewable raw     materials, -   a flexible bulk material container, which is inside the outer     container, wherein the flexible bulk material container has at least     one inner diffusion-impermeable layer with a water vapor diffusion     rate WDD of less than 0.3 g/(m2*d), preferably less than 0.1     g/(m2*d) measured at 38° C. and 90% relative humidity, according to     DIN53122, -   and an oxygen and carbon dioxide diffusion rate q_(A) each of less     than 0.3 cm3/(m2*d*bar), preferably less than 0.1 cm3/(m2*d*bar)     measured at 23° C. and 75% relative humidity, according to DIN53380, -   and an outer flexible layer with an ultimate tensile strength warp     of at least 185 daV/5 cm and an ultimate tensile strength weft of at     least 150 daV/5 cm measured according to DIN EN-ISO 13934-1, from     base and side walls.

Preferably the flexible bulk material container for transporting metal alcoholates, especially magnesium alcoholate, is blanketed with nitrogen.

Oxygen is excluded from within the flexible bulk material container by flushing with nitrogen. In this way self-ignition, which occurs at about 20 to 70° C. depending on volume, can be safely avoided even over a longer period of transport.

The method according to the invention likewise comprises the preferred embodiments of the transport container according to the invention and the above-mentioned alcoholates.

The figures show the various preferred forms of the invention:

In FIG. 1 the flexible bulk material container usable according to the invention has a filling connector 1, an outlet connector 2 and the carry belts 3, 4, 5 and 6.

In FIG. 2 a cardboard box as the rigid outer container 11, in which the flexible bulk material container is inserted, is arranged on a pallet 12. Here the lid flaps 11 a, 11 b, 11 c and 11 d are still open.

In FIG. 3 a closed transport container 9 ready for transport, consisting of the FIBC 10 and the cardboard box 11, is arranged on a pallet 12. It is fixed to the pallet using strapping tape.

CORDSTRAP® polyester strapping tapes, for example, can be used as the straps. 

1. Transport container for metal alcoholates, comprising a rigid outer container, which consists primarily of renewable raw materials, and a flexible bulk material container, which is inside the outer container, wherein the flexible bulk material container has at least one inner diffusion-impermeable layer with a water vapor diffusion rate WDD of less than 0.3 g (m2*d) measured at 38° C. and 90% relative humidity, according to DIN53122, and an oxygen and carbon dioxide diffusion rate q_(A) each of less than 0.3 cm3/(m2*d*bar) measured at 23° C. and 75% relative humidity, according to DIN53380 and an outer flexible fabric layer with an ultimate tensile strength warp of at least 185 daV/5 a cm and an ultimate tensile strength weft of at least 150 daV/5 cm measured according to DIN EN-ISO 13934-1 from base and side walls.
 2. The transport container according to claim 1, wherein the transport container fulfills the criteria for a combination IBC of the type 11HZ2 for the purpose of the European Agreement concerning the International Carriage of Dangerous Goods by Road (ADR) and the International Maritime Dangerous Goods code (IMDG code).
 3. The transport container as claimed in claim 1, wherein the rigid outer container consists primarily of cardboard.
 4. The transport container as claimed in claim 1, wherein the flexible bulk material container is removable from the transport container.
 5. The transport container as claimed in claim 1, filled with a metal alcoholate.
 6. The transport container as claimed in claim 5, wherein the metal alcoholate is selected from the group consisting of magnesium ethanolate, magnesium methanolate, magnesium isopropanolate, or mixed compounds of these; sodium methanolate, calcium ethanolate, calcium methanolate, carbonized magnesium alcoholate or mixtures of these.
 7. The transport container as claimed in claim 5, wherein the weight of the transport container is less than 15% of the total weight of transport container filled with metal alcoholate.
 8. A method for transporting metal alcoholates comprising the steps provision of a transport container, filling of the container with metal alcoholate, a closing of the container and subsequent transportation, characterized in that wherein the transport container comprises the following components: a rigid outer container, which consists primarily of renewable raw materials, and a flexible bulk material container, which is inside the outer container, wherein the flexible bulk material container has at least one inner diffusion-impermeable layer with a water vapor diffusion rate WDD of small 0.3 g (m2*d), measured with 38° C. and 90% relative humidity, according to DIN53122, and an oxygen and carbon dioxide diffusion rate q_(A) each of less than 0.3 cm3/(m2*d*bar), measured with 23° C. and 75% relative humidity, according to DIN53380 and an outer flexible fabric layer with an ultimate tensile warp of at least 185 daV/5 cm and an ultimate tensile strength weft of at least 150 daV/5 cm measured according to DIN EN-ISO 13934-1, from base and side walls. 